The same



OP 180,4t1b

PATENT FFlCE.

eus rxv MAGNUS, OF BERLIN, GERMANY.

IMPROVEMENT IN COMPOSlTlflNS FOR BlLLlARD-BALLS AND PROCESSES OFMANUFACTURING THE SAME.

To all whom it may concern:

Be it knownjthat I, Gusmv MAGNUS, of Berlin, Kingdom of Prussia, GermanEmpire,

' have. invented an Improved Process of Making Billiard- Balls ofVulcanized India-Rubher, of which thefollowingis a specification: Myinvention accomplishes an object long sought without success, namely: Tomake billiard-balls of vulcanized india-rubber, which answers the mostrigid claims on such halls.

. -My balls are uniformly solidthrou hout with-0LlfiTQuyLQOIGSLOMflXlQIQS. may clamor ev re our d tea-height of eighty"seesaw tears giants-lama y n-the center,.o..the ha1l,.

Heretofore it his not been possible to manufactiire rubber balls whichfulfilled all these requirements. They did not reach even the halls madefrom ivory, which are considered to be the best, notwithstanding thatthey do not come up to the standard of perfection.

They are hard and elastic, it is true, but after some usethey lose theircolor, being dyed only on the surface. They crack or peel off. In most.

cases their center of gravity does not coincide with the center of theball itself, as the quicksilver bath will prove, and consequently theydo not run true. Lastly, they are expensive.

The way in which rubber balls are now made is to cure or bakeindia-rubbcr, mixed with sulphur, and with less than fifty per cent. ofother different substances, for a short time,

varying from one and one-half to three hours; but the effect has beenalways to produce an l inferior fabric, as above stated, not even reach-1: ing the quality of ivory balls. After many l expensive trials andexperiments I have sucl oeeded in producing first-rate balls. The mannorof makingthem is as follows: The ingredients are rubber, sulphur, asuit-' able coloring matter, and-heavy spar, or sul- Specificationforming part of Letters Patent No. 180,484, dated August 1, 1876;application filed March 6, 1876.

least fifty per cent. of the rubber.

The mixing is done in the usual way. At-

ter having made a ball, as nearly true as possible, and about one-halfinch smaller than the finished ball, it is enveloped in a sheet of thesame mixture, having the required color, of

three-eighths of an inch thickness, and put in a very strong metallicmold of adequate form.

The whole is then submitted to the curingprocess during at least tenhours, commencing with alow temperature, and increasing it slowly butsteadily. The mixture is exposed only for one hour, or less, to thehighest degree of heat, which will vary according to the quality of theindie-rubber used. The cured balls are then turned and finished.

I am well aware that the vulcanizing and curing of india-rubber isknown; also that' billiard-balls have been made of such rubber,

sisting, essentially, ofinclosing them in 51* oiig metallic molds of therequired form, then sub-- mitting them to a slowly-increasing heat fora... 7

period of ten hours or more, and, finally, turning and finishingthem,substantially as specified.

This specification signed by me in presence of two witnesses this 12thday of January,

GUSTAV MAGNUS.

Witnesses:

HERMANN KREISMANN, 1*.'

WENcEsLAus KLEERODER:- ---.t

phate of baryta, the latter in a quantity at

